Apparatus for indicating or controlling physical changes



June 25,1935. I DE F REZ 2,005,773

7 APPARATUS FOR INDICATING OR CONTROLLING PHYSICAL CHANGES OriginalFiled Oct. 19, 1927 lNVENT OR, 0/3 02 2570/62.

BY 6/3 ATTORNEY5 'UNETE sgggg i FFI APPARATUS FQR INDICATKNG QR 630N-TROLLING PHYSHEAL CHANGES Luis de Florez,

Pomfret. Conn.

Original application October 19, 1927, Serial..No.

ary 5, 1934 12 Claims.

This invention relates to devices for indicating, recording andcontrolling physical changes with respect to the rate as well as thedegree of such change. In its broader and more general aspects, theinvention is concerned with apparatus responsive to pressure and/ortemperature changes in industrial processes. More particularly, theinvention provides a novel combination of mechanical devices which,during a period of changing process temperature or pressure, willmeasure and/or control the rate of such change and during a period ofconstant process pressure or temperature will indicate the magnitudethereof.

Many industrial processes are dependent for their successful operationupon the maintenance of definite pressure or temperature conditions andare adversely affected by changes of undue magnitude or duration. Thepresent invention finds particular utility in the operation control ofsuch processes since the apparatus is responsive to the rate as well asthe degree of such physical changes and therefore regulatory steps maybe intelligently and systematically initiated before the temperature orpressure change has reached its full extent. The invention is further ofparticular industrial value in that the apparatus hereof maybe used inconjunction with any ,di.

instruments. 7/ i The present practice with regard to' indicating,-recording or controlling process temperatures and pressures involves theuse of instruments or devices which continually reflect true or approximately true instantaneous values regardless of whether the temperatureor pressure is constant or changing. Thus at a time of processtemperature or pressure change such devices will reflect a constantlychanging value which measures the instantaneous magnitude of thechanging factor but gives no indication of the rate at which suchchange-is occurring. In the present invention means are provided notonly for indicating instantaneous values but also for indicating valueswhich measure the rate of change as well. This object of the inventionis attained by magnifying the resultant response of the apparatus duringperiods of change and the device so functions that the magnification ofthe temperature or pressure values at a time of temperature orpressurechange is proportional to the rate of such change. Thus a rapidchange in process pressure or temperature will occasion a greater degreeof magnification in the response ed auxiliary measuring or controlDivided and this application February 7, 1931, Serial No. 514,165.

Renewed Februof the apparatus thereto than a more gradual change.

In the attached drawing the figure is a diagrammatic assembly drawing ofone form of the ap-" paratus showing in some detail the several unitsthereof, together with an illustrative adaptation of the apparatus toindustrial pressure control.

Referring to the figure, I0 is a by-pass conduit communicating with afluid conduit 25 leading from an external source of fluid supply (notshown) as, for example, the vaporizer of a cracking unit. A chamber 26filled with a non-compressible fluid may conveniently be placed in theline ID for the purpose of supplying such a fluid to the operativeportions of the apparatus in order that greater uniformity of operationmay be attained. This structure is particularly desirable when a gaseousfluid is the source of pressure. A bellows device I is mounted between astationary support |2 and a spring l3. The pipe I4 establishescommunicationbetween the conduit l0 and the bellows II and the pressureof the external system is transmitted therethrough to the said bellowswhich in turn acts upon the arm I 5 through the medium of the link l6.At its opposite end the arm I5 is attached to a link l8 connecting saidarm with the lever l1 pivoted at H.

The bellows devices 2| and 2| also communicate with the by-pass conduitl0 and transmit pressure therefrom to the free end of the lever I1 andthence through the link I8 to the arm IS. The bellows 2| and 2| are inopposed relation and communication .between the fluid spaces thereof isprovided by the pipe 22 carrying the valve 23 by means of which thetransmission of the full line pressure in the conduit II) to the bellows2| may be delayed for a regulable period of time. The springs 24 and 24'are interposed between the free end pf the lever l1 and the bellows 2|and 2 re ectively in order to provide at a time of change in the mainline pressure, the

springs 28 and 29 acting upon the lever. H are provided: tocounterbalance a portion of the direct ing a control valve 21.

pressure of the bellows 2I or 2 I (depending upon the direction of thepressure change).

The arm I5 is provided, intermediate its ends, with a cross-head I9 towhich is attached a rod 20 actuating a gauge arm G. The gauge arm G ispivoted at the point 32 and one end thereof acts as a pointer forindicating purposes while the opposite end is connected to a link 33operat- It is to be understood of course that the indicating and controlmechanism aforementioned is presented merely as an illustrativeadaptation of the apparatus for control purposes and in no way limitsthe scope of the invention with respect to its industrial application.It will also be noted that a continuous indication of instantaneous mainline pressure values (as compared with the indication of the rate ofpressure change by means of the gauge G) may be obtained if desired byattaching to the rod I6 at its lower end a gauge arm and pointer (notshown) acting upon a suitably calibrated scale.

When adapted to the indication and control of pressure in a vessel orconduit adjacent thereto, the operation of theapparatus is as followsiAssume that the same pressure exists in the bellows II, 2| and 2I' (asduring a period of constant process pressure), the valve 23 beingpartially closed. The control system is then in a state of equilibrium,the arm I1 is horizontal, and the control valve 21 maintains a constantefliux through the fluid conduit 25. If a sudden increase in processpressure occurs the bellows I I and 2| are affected immediately andoccasion a downward movement of the two ends of the arm I5. The endacted upon by the bellows I I will be depressed an amount proportionalto the degree of process pressure increase while the depression of theend acted upon by the bellows 2I will depend upon the design for theapparatus and may or may not be equal in magnitude to the depression ofthe opposite end. Assume that the various elements of the apparatus havebeen so proportioned as to occasion the same initial depression of bothends of the arm I5 at a time of process pressure change. The said armwill then maintain a horizontal position during its downward movement.The initial response of the gauge G and the control valve 21 will thenbe magnified one hundred percent. In other words, the control valve willopen, say, twice as much as is proportionately necessary tocounterbalance the actual instantaneous process pressure increase andthus anticipates and forestalls a further increase in said pressure.

The bellows device 2| is also allected by the aforesaid increase inprocess pressure but, due to the interposition of the valve 23 in theline 22, the full response thereof is delayed and the time intervalinvolved in any particular case will depend upon the setting of thevalve 23, tension in the springs 28 and 29, and the relative positioningof the several contact points on the lever arm II.

During the said lag period the pressure in the bellows device 2| willgradually build up to a value equal to the pressure in the bellows 2|.This. gradual response will occasion a gradual raising of the lever armI1 to its original horizontal position which in turn affects a graduallifting of arm I5 at' the end attached to the link I8. The magnifiedresponse of the control valve 21 to the initial pressure change isthereby com-' pensated at a predetermined rate which is based upon rateof process pressure change and the needs or characteristics of theindustrial process being controlled. Thus if the process pressurecontinued to increase the full compensation of the initial magnifiedresponse of the control apparatus would be deferred much longer thanunder conditions involving a relatively rapid return of the processpressure to the proper level.

When the invention is adapted to control as well as indication ofpressure changes (as in the illustrative assembly) the pressure in eachof the several bellows devices will eventually return to the originalvalue corresponding to the predetermined proper process pressure, andboth the arm I5 and the arm I! will revert to horizontal positions attheir respective original levels, after the said process pressure hasre-attained its datum level. If, however, the invention is appliedmerely to the indication of pressure and pressure changes, then bellowsII, which at all times reflects the actual process pressure value, willnot necessarily bring the arm I5 back to a horizontal position. .Thelever arm II will always be horizontal when the pressures in the bellows2| and 2I' are equal and thus the end of the arm I5 moved by the link I8will always revert to its original starting point after a sufficientperiod of constant process pressure. The position of the end of the armI5 moved by the link IE will on the other hand depend upon the actualinstantaneous value of the process pressure since no compensation isprovided for the response of the bellows II thereto.

In the preceding description of the operation of this invention, examplehas been made of an application thereof to process pressure indicationand control and the response of the apparatus to a positive pressurechange has been discussed. The relative simplicity of the operationnecessitates no further discussion thereof in connection with pressuredecreases since the difference is one of direction only. The adaptationof the invention to the indicating and controlling of processtemperature and temperature changes calls for little elaboration of thepressure control operation. In either case the apparatus properfunctions in the same manner. When, however, the physical changeinvolved is one of temperature the conduit I0 is connected to a bulb orother suitable vessel containing a fluid capable of oreating a pressureproportional to the temperature to which it is subjected. The bulbcontaining such a fluid is then located at a desired point in theprocess equipment where it will be responsive to the temperature whichit is desired to control and process temperature fluctuations,translated as pressure changes within the control system, will occasionthe functioning of the apparatus as previously discussed.

In the description of the invention as shown in the attached drawing,the mechanical devices provided for occasioning a response in theapparatus to physical changes in an external system communicatingtherewith have been de picted as collapsible bellows (indicated by thereference numerals II, 2| and 2I' in the drawing) In the industrialapplication of the invention it is contemplated that the aforesaidbellows devices may be supplanted by other devices mechanicallyequivalent to said bellows. For example, such a modification of theinvention might comprise the substitution of a flexible diaphragm,acting directly or indirectly, or through an arrangement of springs,upon the several levers actuating the indicating and controllingmechanism. This and other modifications of the invention logicallyconcerned with the practical use thereof are to be considered wellwithin claims when I refer to an apparatus for controlling changes ofeither temperature or pressure, I mean to include within such termdevices for indicating such physical changes of temperature or pressure.Such indicating devices are frequently used as essential elements in thecontrol of such physical changes in a system.

This application is a division of my copending application, Serial No.227,345, filed October 19, 1927, and issued Dec. 22, 1931, as. PatentNo. 1,837,853. a

I claim:

1. An apparatus for controlling changes of temperature or pressure in acontrolled system by means of responsive pressure changes in an adjacentsystem, which comprises in combination a first mechanical device, aconnection between said first mechanical device and said 'adjacentsystem whereby said first mechanical device responds fully. andimmediately to a change of pressure within said adjacent system, asecond mechanical device, a connection between said second mechanicaldevice and said adjacent system whereby the initial response of saidsecond device'to'the said change is full and immediate, a mechanicaldevice, a third connection between said third mechanical device and saidadjacent system, said third mechanical device being so related to saidsecond device that the full response of one neutralizes. the fullresponse of the other, means for delaying the full response of the sadthird device to said change in said adjacent system, and control devicesoperated joinly by said mechanical devices.

I 2. Control apparatus actuated by pressure changes in an adjacentsystem, which comprises in combination a firstmechanical device, aconnection between said first mechanical device and said adjacentsystem-whereby said first mechanical device responds fully andimmediately to a pressure change within said adjacent system, a secondmechanical device, a connection between said second mechanical deviceand said adjacent system whereby the initial response of said seconddevice to the said pressure change is full and immediate, a thirdmechanical device, a connection between said third mechanical device andsaid'adjacent system, said third mechanical device being so related tosaid second device that the full response of one neutralizes the fullresponse of the other, means for delaying the .full

response of the said third device to said pressure change in saidadjacent system, and control devices operated jointly by said mechanicaldevices.

3. An apparatus for controlling temperature changes in a controlledsystem by means of responsive pressure changes in'a'n adjacent system,which comprises in combination a first mechanical device, a connectionbetween said first mechanical device and said adjacent system wherebysaid first mechanical device'responds fully and immediately to apressure change within said adjacent system, a second mechanical device,a connection between said second mechanical device and said adjacentsystem whereby the initial response of said second device to the saidpressure change is full and immediate, a third mechanical device, aconnection between said third mechanical device and said adjacentsystem, said third mechanical device being so related to said seconddevice that the full response of one neutralizes -the full response ofthe other, means for delaying the full response of the said third deviceto said pressure change in said adjacent system, and control devicesoperated jointly by said mechanical devices.

4. An apparatus for controlling changes of temperature or pressure in acontrolled system by means of responsive pressure changes in an adjacentsystem, which comprises in combination a first bellows device,meansadapted to permit communication between said first bellows device andsaid adjacent system, whereby said first bellows device responds fullyand immediately to a change of pressure within said adjacent system,- asecond bellows device, means adapted to permit communication betweensaid second bellows device and said adjacent system, whereby .saidsecond bellows device responds immediately to the said change withinsaid adjacent system, a third bellows device, means adapted to permitcommunication between said third bellows device and said adjacentsystem, means for permitting a full response of said second bellowsdevice to neutralize the full response of said third bellows device,means for delaying the full response of said third device to the saidchange within said adjacent system, and control devices operated jointlyby said bellows devices. v

5. Control apparatus actuated by pressure changes in an adjacent system,which comprises in combination a first bellows device, means adapted topermit communication between said first bellows device and said adjacentsystem, whereby said first bellows device responds fully and immediatelyto a pressure change within said adjacent system, a second bellowsdevice, means adapted to permit communication between said secondbellows device and said adjacent system, whereby said second bellowsdevice responds im mediately to said pressure change within saidadjacent system, a third bellows device, means adapted to permitcommunication between said third bellows device and said adjacentsystem, means for permitting a full response of said second bellowsdevice to neutralize the full response of said third bellows device,means for delaying the full response of said third device to saidpressure change in said adjacent system, and control devices operatedjointly by said bellows device. 1

6. An apparatus for controlling temperature changes in a controlledsystem by means of responsive pressure changes in an adjacent system,which comprises in combination a first bellows device, means adapted topermit communication between said first bellows device and said adjacentsystem, whereby said first bellows device responds fully and immediatelyto a pressure change within saidadjacent system, a second bellowsdevice,-

means adapted to permit communication between said second bellows deviceand said adjacent system, whereby said second bellows device respondsimmediately to said pressure change within said adjacent system, a thirdbellows device, means adapted to permit communication between said thirdbellows device and said adjacent system, means for permitting a fullresponse of said second bellows device to neutralize the full responseof said third bellows device, means for delaying the full response ofsaid third device to said pressure change in said adjacent system, andcontrol devices operated jointly by said bellows device. '7. In acontrol apparatus, two pressure actu- -\ated mechanical devicesconnected for move-' ment in opposition to one another, a conduitcontaining fluid of varying pressure, separate connections between saidconduit and said mechanical devices, a resistance interposed in one ofsaid connections for delaying the full movement re- --.sponse of therelated device to a change of pres- 8. In an apparatus for controllingchanges of temperature or pressure in a controlled system by meansresponsive to pressure changes in a pressure system, two directlyconnected similarly constructed mechanical devices communicating withsaid pressure system and actuated by pressure changes therein, means foroccasioning movement of one of said devices in full and immediateresponse to said pressure changes, means for delaying the full movementresponse of the other of said devices to said pressure changes, the saidmovement of each of said mechanical devices being directly dependent onthe movement of. the other and occasioning a movement differentialtherebetween, the magnitude of said movement differential being afunction of the rate of said pressure changes, and means fortransmitting the eifect, of said movement differential tooperation-control devices.

- 9. In an apparatus for controlling changes of temperature or pressurein a controlled system, a fluid-containing conduit, means'for causingthe pressure of the fluid in said conduit to vary in response to changesof temperature or pressure in said controlled system, a first bellowsdevice communicating directly with said conduit and actuated by thepressure therein, whereby said first bellows device responds fully andimmediately to a pressure change in said conduit, a

second similarly constructed bellows device directly connected withsaid'first bellows device and communicating through a resistance withsaid conduit and actuated by the pressure therein, whereby the fullmovement response of said second bellows device to said pressure changein said conduit is delayed, the said movement of each of said bellowsdevices being directly dependent on the movement of the other andoccasioning a movement differential therebetween, the magnitude of saidmovement differential being a function of the rate of said pressurechange, and means for transmitting the eifect of said movementdifferential to operation-control devices.

10. In an apparatus for controlling changes of temperature or pressurein a controlled system by means responsive to pressure changes in apressure system, a mechanical device communicating with saidpressuresystem, which device first responds fully and immediately to apressure change in said system and then retracts said response inaccordance with the rate of said pressure change, and meanscommunicating with said mechanical device for operating control devicesin said controlled system in accordance with changes effected in saidpressure system and transmitted to said control devices through theintermediary of said mechanical device.

11. In an apparatus for controlling changes of temperature or pressurein a controlled system, two mechanical devices communicating with saidcontrolled system and actuated by changes of temperature or pressuretherein, means for occasioning movement of one of said devices in fulland immediate response to said changes, means for delaying the fullmovement response of the other of said devices to said changes, the saidmovement of each of said mechanical devices being independent of themovement of the other and occasioning a movement differentialtherebetween, the magnitude of said movement differential being afunction of the rate of said changes of temperature or pressure,and-means for transmitting the effect of said movement differential tooperation-control devices.

12. In an apparatus for controlling changes of temperature or pressurein a controlled system,- a fluid-containing conduit, means for causingthe pressure of 'the fluid in said conduit to vary in response tochanges of temperature or pressure in said controlled system, a firstmechanical device communicating with said conduit and actuated by thepressure therein, means for occasioning movement of said first device infull and immediate response to a pressure change in said conduit, asecond mechanical device communicating with said conduit andactuated bythe pressure therein, means-for-delaying the full movement response ofsaid second device to said pressure change in said conduit, the saidmovement of each of said devices being independent of the movement ofthe other and occasioning a movement differential therebetween, themagnitude of said move ment differential being a function of the rate ofsaid pressure change, and means for transmit: ting the effect of saidmovement differential to operation-control devices.

LUIS DE FLOREZ.

